Total Synthesis of PDE-II

抄録

Starting from 7-hydroxy-6-methoxy-indole (III) PDE-II (II), a new inhibitor of cyclic adenosine 3', 5'-monophosphate phosphodiesterase and the first substance which has 1, 2-dihydro-3H-pyrrolo[3, 2-e]indole skelton, was synthesized in eight steps. The key inter-mediate, 1-acetyl-5-amino-2, 3-dihydro-7-hydroxy-6-methoxy-indole (VIII), carring necessary substituents was obtained from III in five steps. Coupling of the diazoniumsalt of VIII with ethyl 2-acetylpropionate followed by acid catalized cyclization and alkaline hydrolysis afforded II.